Illuminating device



Jan., 9, 1940.v J. McCLAlN ILLUMINATING DEVICE Filed Feb. 6, 1956 /A/VE/VTOE: v daf//VMfC/l//v an' l Arme/v5 w\.. L QN Patented Jan. 9,y 1940 ELS ' V`Imiuivniwri1Nerfinivior:1 i n :161m McClain, ichfiagp, L111. zlApplieaiin/Februaiyf s, isssseiial No. 62595 V2 Claims; 'i (ci. 24o-2.13)

!Thisinvention relates generallyftoilluminat# ingfdevices arid more particularly toA devices-for illuminating *l the :interior surfaces of vtubes vfor purposes-fof inspection. 1

After -afperio'dic'cleaning of tubes, having par- -ticiilawreference ltof'th'ose used in stills, boilers, `and-'the -lik`e,-it is necessary'to thoroughly in* spectltheinteriorl-sufaces thereof, sov that lany `whichl -are vbadly corroded-or which have bulges or vholloWs in their Walls, may be discovered `and replaced before-actual failure occurs.

The presentimethod, `of inspection includes placing a light, usuallyano'rdinary pocketflashllight or :the like,:in onelend of the tubeiand Iviewingthe'interioisurface from the uother end. -vThis methodhas ;the .disadvantage 'that direct rays 'f1 'om}t'hev source of light pass directly through the At11be..and.strike,the eye of the-inspecter.v This [glare-naturallyiimpairs the ei- .ciency of inspection -as Well vlas .being injurious and annoying to .-theinspecton As these --ill intensity of illumination on the effects .increase Withincreasing.intensity -of the sourceof light, iit is-necessary to usega light of comparatively low intensity, consequently the surface to .-.be finspected cannot be illuminated to the extent that is requiredfor maximumy than that from the illuminating device, in order4 to further insure freedom from glare.

Still another object relates to provision for adjusting the directed light, to accommodate the illumination to tubes of different lengths and diameters so thatlight Will be supplied to substantially the entire inside surface.

I Will now describe an embodiment of my invention, reference being had to the drawing appended to, and made a part of this specication, in which Figure 1 is a sectional elevation of a device embodying the principles of my invention, taken.

along a line I-l in Figure 2.

v -itricL shown, by means-of the guiding surface l2.

' '.-device,fshowing l'the method off operation.

f icompif-i'sirigfan electriclamp -hel'dI in "a socket ivl, which -in 'fturn,fislkfastend toA l*the vWall 4 rby al hollow threaded postiv 8 and. a 'finut i9. An elecsupply cable jl il 'exte'nds through vthe hollow i3 t28 intothe-socket l, where'-suitable'connec- "tionds'n'iade. The lamp is dispo's'ed substantially ion-thelongitudinalaxisbf the housing 2.

. AThelhulsingl'is'provi'ded'with a distendedporiti'on 5H yfvvl-ii'ch Ipresen'ts fa frusto-co'nical"surface l2 that is substantially coaxial to the f housing vLitself. 'A'r'i'extnded '.-1ip"|i3 encircle's the 'open 'end "3 f the housing', vnthe interior surface I4 of' the lip l I3 bing tapered inwardly.

' 5A ffrusto-iconical fmember i5; jmade of 'any opaqueimateriar 'is disposed 'in the. open en d 3 siibstai-itially nth'e longitudinali Ya'JXi's' 4lo'if the rhousing and in alignment with the light source. It has a reduced `threaded lsupporting portion `It u which screws into a tapped lug l'l. This lugis supported from the housing on a pair of arms of brackets I8, which can be seen in Figure 2.

Hence by rotating the member 15 ',around'its longitudinal axis,v its position can be adjusted along the axis, and can be set closerto, or farther from, `the lamp 6 as desired.

. The end of a tube `I9y is indicated'in Figure 2.

' To place the device I in operating position, the

housing is placed with its openend 3 in register with the end ofthe tube, and then inserted until the frusto-conical surfacel I2 engages the tube I9. By holding the housing parallel to the tube,

it can then easilygbe guided into the position In the operatingpositionf the axis of the housing fallssubstantially onthe axis of the tube, and daylight 'and other light from exterior sources are shut out ofthe tube by the surface l2 of lthe rays 'from the light source are intercepted and diverted by means of the intercepting member I5 from the central space B of the conical beam A.

Figure 3 illustrates this eifect as produced throughout the length of the tube 3. The space I recognize, of course, that there will in fact,

be no clearly defined shadow in the centrali space B as shown, as this space will be illuminated by reflected light. The illustration is made in this way in order to show the space from which direct light rays are excluded.

By'screwing the intercepting member I5 to-` ward or away from the light source, the` crosssectional area of this shaded portion B at the' end 20 of the tube, can be enlarged or contracted, and the distance that light from the lamp 6 is projected along the interior of a given tubey can thus be adjusted.

Furthermore adjustments' can be made for dfferent lengths and sizes of tubes. For example, if the device were to be used without adjustment to illuminate another tube of greater length or smaller diameter than the one shown in Figure 3, the beam of direct light rays would not reach the surface of the tube `near the far end 20, hence an adjustment of the intercepting member I5 away from the source of light would be required. Conversely if a shorter or larger diameter tube were inspected, `an adjustment of l the member toward the lamp would be desirable to prevent direct light rays from the source from passing directly through the tube and out of the `other end.

Having thus eliminated direct, glaring rays 'from the lamp from the point of view, it is possible to use a lamp of appreciably higher intensity than those employed heretofore, thereby raising the intensity of illumination at the interor Surface i?! gf the tube to any extent that is found to be desirable and conducive to more efficient inspection.

I do not intend to limit my invention to the details shown and vdescribed herewith, but what I desire to protect by Letters Patent of the United States is set forth in the following claims.

I claim:

1. A device for illuminating the interior sur- Vfaces' of tubes for inspection purposes, said device comprising a portable tubular` housing having an open end adapted for insertion into one end of a tube, a source of light within said hous- ,1; ing, a distended portion on said housing for engaging the end of said tube for shutting out other light than light from said source and for guiding ysaid housing so that said source of light can be easily centered on the longitudinal axis of said tube, an opaque member supported by said housing in substantial alignment with said source of light on the axis of the tube in a position between said source andthe far end of the tube,4 for preventing direct rays' of light from said source from passing directly out through said far end of the tube, and means for adjusting the position of said member with respect to sai'd light source.

2. A device for illuminating the interior surfaces of tubes for inspection purposes, said device comprisingv a portable tubular housing having an open end adapted for insertion into one end of a tube, a source of light within said housing, a portion of said housing being adapted to engage the end of said tubefor shutting out other light than light .from said source and for guiding said housing to facilitate centeringthe'source of light on the axis of lsaid tube, a frusto-conical f light intercepting member disposed adjacent the open end of said housing and in a position with the axis of said frusto-conical member substantially coaxial with the longitudinal axis of the'v housing and with the smaller kend of the mem- 'lis 

